Add water flickering option

[Ygarr]

TODO

• [x] Allow to choose between original water (flickering) and no flickering water
• [x] Add option to Launcher

Original comment

Strange not smooth water behavior like this: 40-50-60 FPS

FYI: If make video with 15 FPS water distort almost disappears like here:

[DjThunder]

Here the original: https://youtu.be/NjV5u-n6NAM?t=908 Water waves are displayed 1/2 or 1/3 per frame (which cause glitch feeling). I guess it was like this because of fps saving to let more resources for other stuff. So I kept the same rendering.

Maybe I can add an option to toggle an alternative effect. I will check that !